318i no spark cylinder #2 - Need HELP !!

singring

New Member
Messages
18
Likes
0
Location
Saskatoon SK Canada
#1
Boy, do I need your help here...my 1995 automatic 318i refused to start the other day. It was cold out ( -20 C ), but I drove it to work, then tried to start it at lunch hour. The starter turned over fine, but the engine just wouln't fire. I kept trying, and the battery was getting pretty low to the point of not turning the sarter over. So I tried to get a boost (followed the boosting instructions, as per the driver's manual). The starter would turn over fine, but again the car would not start. I had it towed home.
I got the car into my garage, and plugged in the block heater, and left it over night. The next day, I again tried to start it, and almost got it going, so I used my other car to give the 318 a boost. I got it going, but was only firing on 3 of 4 cylinders. I removed the spark plugs, and cleaned them, they were really black. Then I started the 318 again, still not firing on one cylinder. I kept it running to clean out any carbon, then after a couple of minutes, I see from the open hood, smoke coming off the coil-pack. I stopped the engine, and found that a big hole had been burnt out of the side of the coil-pack where the #2 coil was. I ordered a new coil-pack, got it the next day, installed it and the #2 cylinder is STILL not firing.
I switched the #2 spark plug with #1, STILL not firing on cylinder #2.
I switch the #2 spark plug wire with #1, STILL not firing on cylinder #2.
Then I found a site that showed how to find out the ECM was holding any codes. Turns out that the ECM was holding code 1271, which means

" an open-circuit or ground fault in the ignition wiring has occurred with an ignition coil. Place timing light on the ignition wires and check for a signal. Also check the wires for faults, and check the spark plugs, too. "
There are no other codes present.

This seems an obvious code for my #2 cylinder, but I've already narrowed my search and eliminated the spark plug, and the spark plug wire. I have yet to see if the is any signal being sent to the #2 coil, of the coil-pack, but I can guess that there is none.

Any ideas, before I have the car towed to my mechanic ??

Thanks
 

singring

New Member
Messages
18
Likes
0
Location
Saskatoon SK Canada
#2
I'm back with some good news, and some advice....I removed the DME from my car, and opened it up. The first thing I noticed was the dreaded smell of scorthed electronics. Then on the underside of the cover I see a slightly darkened area which took the heat from the electrical fault. I checked over the circuit board, and the only place of concern is a circuit "line" on the board where the board coating is blackened, charred if you will, about half-way along that line. I grounded myself before touching the circuit board, then with a very fine screwdriver, I was able to scrape away the charred material, under which I discovered a break in the circuit line. Tomorrow I will take the DME to work with me, and have one of the on-site electronics technicians solder the circuit line, and re-coat over it with board insulator.
I am 99% sure that this break was a result of the ignition coil-pack shorting out the #2 coil, which then caused the DME failure.

After discovering all of this, and the euphoria wore off (hopefully, nothing else on the DME faulted), I re-examined the original burnt-out coil-pack. When comparing it with the new coil-pack, I can see hair-line cracks on the original. I remember reading somewhere that these cracks can cause arcing on the coils.

A few words of advice: have a good look at your coil-pack (or, the individual coils on a 6 cylinder), check for ANY cracks, and replace the coil-pack/coils
before you do damage to your DME (My coil-pack was an inexpensive $176 Canadian). Second, if you do need to replace your DME, open it up, and check for any obvious faults. You've got nothing to lose, since you were going to replace it anyway. An able electronic tech can do some fine solder work for you for a few bucks, as opposed to having the whole unit replaced for $1000. You may get lucky.

My story will continue, after I try the repaired DME tomorrow. I have every limb and appendage crossed, and I WILL say my prayers tonight. This will be a very Merry Christmas if this does the trick.
 


Top